From 4e59747cea428d39c80974c408e95ba86bf63ecc Mon Sep 17 00:00:00 2001
From: Pierre Ducroquet <p.psql@pinaraf.info>
Date: Fri, 13 Jul 2018 12:47:36 +0200
Subject: [PATCH] Fix segfault with lca('{}'::ltree[])

---
 contrib/ltree/_ltree_op.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/contrib/ltree/_ltree_op.c b/contrib/ltree/_ltree_op.c
index 9bb6bcaeff..6afcd95cd1 100644
--- a/contrib/ltree/_ltree_op.c
+++ b/contrib/ltree/_ltree_op.c
@@ -297,6 +297,9 @@ _lca(PG_FUNCTION_ARGS)
 	ltree	  **a,
 			   *res;
 
+	if (num == 0)
+		PG_RETURN_NULL();
+
 	if (ARR_NDIM(la) > 1)
 		ereport(ERROR,
 				(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
-- 
2.18.0